[C#]
    byte[] Key;
    TElCustomCryptoKey Key;

[VB.NET]
    Property Key As Byte()
    Property Key As TElCustomCryptoKey

[Pascal]
    property Key : ByteArray; {array of byte}

[C++]
    void get_Key_ByteArray(std::vector<uint8_t> &OutResult);
    void set_Key_ByteArray(const std::vector<uint8_t> &Value);

[PHP]
    string get_Key()
    void set_Key(array of byte|string|NULL $Value)

[Java]
    byte[] getKey();
    void setKey(byte[] Value);